In recent years, acts of making illegal connection called “tampering” to a component for transmitting/receiving a communication signal, such as a circuit board, an IC chip, or a connector or a cable connecting boards, and illegally reading out the communication signal thereby have been considered as a problem. The structure for preventing the tampering is therefore sought after.
Particularly in information processing devices for directly handling personal information, in particular, information on money or property, such as a credit card payment terminal and an ATM, high-level security is required to prevent the information from being stolen or illegally used by tampering.
Known structures for preventing the tampering include a structure in which a component that can be subjected to tampering is covered to make it difficult to make external illegal connection and a structure in which the device itself is broken when a component is detached for attempting illegal connection (Patent Literature 1).
Although not aimed at preventing tampering, the following structure is also known. In order to prevent wiring in a cable from contacting with an external conductor to be short-circuited, the periphery of the wiring is covered by a cylindrical conductor layer applied with a predetermined voltage, and, when the external conductor comes into contact with the conductor layer to change the voltage, this change is regarded as a sign of short-circuit and a warning is issued (Patent Literature 2).